Ground hole forming machine

ABSTRACT

A machine is disclosed having a hammer for impact forming a ground hole. The hammer works within a hammer guide the lower end of which may be biased into ground penetration during hole forming to serve as a casing. The hammer guide assembly is slidably carried within an elongate framework which is positionable to the side of a vehicle for hole forming along roadways. Support means adjustably suspends the framework to position same over the hole site. Positioning cylinders move the lower end of the framework into place. Locking means prevents undesired framework movement during hammer operation.

United States Patent 1 Christensen I Jan.- 16, 1973 [54] GROUND HOLE FORMING MACHINE [76] Inventor: Vernon E. Christensen, P. O. Box Pnmary ExammerflEinest Purser 728 Yoncaua, 0mg 97499 Att0rney-James D. Givnan, Jr. [22] Filed: April 16, 1971 [57] ABSTRACT [2l] Appl. No.: 134,762 A machine is disclosed having a hammer for impact forming a ground hole. The hammer works within a hammer guide the lower end of which may be biased 2% C into ground penetration during hole forming to serve 1 5 28 as a casing. The hammer guide assembly is slidably [58] FR 0 l 2 carried within an elongate framework which is posi- 175/19 3 tionable to the side of a vehicle for hole forming along roadways. Support means adjustably suspends the [56] References C'ted framework to position same over the hole site. Posi- UNITED STATES PATENTS tioning cylinders move the lower end of the framework into place. Locking means prevents un- R25,060 10/1961 Roland ..l75/23 desired framework movement during hammer opera- 3,026,949 3/1962 Eldridge et al. ..173/28 X fl 3,507,338 4/1970 McWaters ..l75/l9 X 3,548,604 12/1970 Campbell ..l75/2O 7 Claims, 6 Drawing Figures PATENTEDJAH 16 ms SHEET 1 [IF 2 ISA INVENTOR. VERNON E. CHRISTENSEN PATENTEUJAH 16 1975 SHEET 2 [1F 2 AGENT GROUND HOLE FORMING MACHINE BACKGROUND OF THE INVENTION The present invention relates generally to equipment and a method for impact forming a ground hole for the reception of a post.

The prior art, to the extent known, encompasses equipment of various designs for the forming of ground 1 holes by successive blows of a hammer or stomper element reciprocated within an upright guide. Additionally, the prior art includes structure permitting the hammers weight to be used for urging a hole casing downwardly about the ground hole to preserve the hole during forming. One such apparatus is disclosed in the U. S. Pat. No. Re. 25,060 issued Oct. 24, 1961 to F. E. Roland. The present invention, in distinction to the R- land arrangement, provides for continuous downward urging of a hammer guide tube by pressure responsive cylinders with said guide tube functioning dually to guide the hammer throughout its fall and additionally as a casing to preserve the hole being formed. Additional differences will be subsequently evident.

Forming a ground hole with prior art machines by repeatedly impacting a hammer renders precise hole forming difficult as the substantial impact forces tend to impart undesired movement to the supporting equipment which desirably is in the form of a rubber tired vehicle for highway travel. The guide means for the hammer is usually of considerable height and when suspended in a plumbed condition from a supporting mast arrangement is susceptible to such hammer induced displacement.

In some hole forming operations a casing is incrementally driven into the hole to prevent collapse of the hole wall. The installation of such casings by existing devices entails the interruption of hammer operation for the reason that the hammer is additionally used as a driving instrument for the casings. Accordingly, the hole forming operation and the casing insertion must be accomplished as two different steps each done in an alternate manner and requiring time consuming structural changes to the device for each step.

Prior art machines additionally require swinging of the hole forming equipment away from the hole formed to allow insertion of the post with return of the equipment over the hole being required if the post itself is to be impacted by the hammer all of which requires precise, time consuming effort.

SUMMARY OF THE INVENTION The present invention is embodied within a machine for the forming of ground holes by impaction of a hammer working within a guide the lower end of which, during hole forming, is in continuous biased insertion in the ground. The guide assembly for the hammer includes a tube with laterally carried slide members which slidably mount the hammer guide for rectilinear travel in an upright framework.

The upright framework, within which said hammer guide assembly moves, is coupled to a supporting vehicle adjacent the frameworks lower and upper ends. Spaced apart tubular guides of the framework slidably house the above-mentioned slide members of the hammer guide. The framework is suspended at its upper end by a supporting structure which in turn is carried by adjustable mast means projecting upwardly from the vehicular base. The lower end of the upright framework is also coupled to said base by positioning cylinders to permit plumbing of the framework in place to insure vertical hammer motion. Locking means serve to prevent undesired framework movement during hole forming.

An important feature of the present invention is the 0 provision of a hammer guide assembly positionable in axial alignment with the hole to be formed and adapted to be progressively and continuously urged into ground penetration to, in effect, provide a casing for the hole being formed while additionally serving continuously to guide successive falls of the hammer along a fixed vertical axis. The guide includes a door to permit placement of a post into the hole being formed without removal of said guide or its surrounding framework.

Important to the present equipment is the upright framework along which said hammer guide assembly moves and which framework is adjustably coupled to the vehicular base adjacent its upper and lower ends to facilitate positioning the framework to suit the requirements of the job at hand. In the forming of ground holes for the reception of guard posts along a roadway, the inclination of the roadway, the road shoulder, the depth of the hole to be formed and its distance from the vehicular base all contribute to the desirability of a highly positionable framework for precise hammer operation. The framework is supported at its upper end in a manner permitting a wide range in both elevation of the framework as well as outward disposition from the vehicle base. Rotational movement of the framework about its upright axis is also provided for by said positioning cylinders which are coupled to the lower end thereof and which cylinders also provide for accurately plumbing of the lower end of the framework in place prior to commencing hammer operation. The positioning cylinders also supplement the action of a locking cylinder. Visual indicators conveniently located within the oper'ators field of vision insure the frameworks plumb being monitored at all times.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. I is a side elevational view of the ground hole forming machine embodying the present invention and shown supported on a vehicular base equipped with a turntable,

FIG. 2 is a horizontal sectional view taken downwardly along line 2 2 of FIG. 1 showing details of the upright framework, hammer guide assembly, and positioning means associated with the framework,

FIG. 3 is a plan view of the support structure of the present machine taken downwardly along line 3 3 of FIG. 1,

FIG. 4 is a side elevational sectional view of the upper end of the support structure taken approximately along line 4 4 of FIG. 3,

FIG. 5 is a front elevational view of the support struc ture taken along line 5 5 of FIG. 4, and

FIG. 6 is a diagrammatic view of the framework positioning cylinders and locking cylinder and related components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With continuing reference to the drawings wherein applied reference numerals indicate parts similarly identified in the following specification, the reference numeral 1 indicates a vehicular base mounting a turntable 2 of a substantially conventional crane machine 3 and permitting the crane to swing the following described hole forming machine into position adjacent either vehicle side or to the rear of the vehicle for transport. In FIG. 1 the vehicular base 1 is preferably selfpowered and may include the mounting of additional instrumentalities such as a powered auger and a boom usable in hole forming and post setting operations. The vehicular base 1 is shown parked alongside a road shoulder S with the crane machine 3 transversely positioned thereon.

The crane supporting the present invention may be of existing design with the powered cable winches preferably having air actuated friction bands for positive setting and quickrelease. The power source for the crane 3 may additionally power both hydraulic and air compressing means providing pressurized fluid and air to the hydraulic and pneumatic components of the hole forming machine. A cab 4 of the crane advantageously locates the machine operator, seated at 5, in close proximity to the work being done. The operator is provided with air and hydraulic valve consoles (not shown) for'convenient operator control of the following described machine.

With continuing reference to FIG. 1 an elongate I framework is indicated generally at and comprising a pair of spaced apart, tubular guides 11 each having an inwardly facing slot (FIG. 2) at 11A. The upper ends of the two framework guides 11 are interconnected by a crosspiece 12 which, as best viewed in FIG. 4, encloses the guides upper ends with the guide ends welded in place within the crosspiece. Also welded to the crosspiece is the lower plate of a pair of load bearing turntable plates described in connection with the later described support structure.

The elongate framework 10 includes a guide retention plate 13 of a heavy plate through which the guides 11 extend for securement by welding as seen in FIG. 2. The guide retention plate 13 also serves to mount rod ends 14A, 15A and 16A of hydraulic cylinders l4, l5 and 16 mounted universally at their base ends on the crane 3 as shown in FIG. 6. The cylinders 14 and 16 are of the double acting type, and as viewed in FIG. 6, may work as a pair to position the guide retention plate 13 outwardly from the crane or moving their piston rods in opposite directions to rotate plate 13 and framework l0 about the latters upright axis. The third cylinder 15, attached centrally to retention plate 13, is a locking cylinder, which supplements the holding action of the first described pair of cylinders, when they are in a hold" condition. Cylinder l5, referred to as the locking cylinder, is serviced at its ends by hydraulic lines 19 with both lines being simultaneously closed or opened by valves 19A to permit blocking fluid flow from and to the cylinder 15. An air cylinder actuates valves 19A while a pressurized reservoir R provides a fluid supply.

The cylinder 15 is locked only during operation of the hammer.

Housed within each tubular guide ll of the framework is a cylindrical slide member 17 comprising part of a hammer guide assembly indicated generally at 18. The slide members 17 are of a diameter to provide a working fit within the tubular guides as seen in FIG. 2. Each slide member 17 carries a lengthwise extending bar 20 which occupies slotted areas at 11A in the tubular guides and to which bars are welded angle irons 21. The bars 20 are inset into the tubular guides 17 to facilitate a secure weld. The bars 20 are additionally grooved lengthwise to receive the apex of each angle iron 21 again to facilitate a secure weld therealong.

The flanges of each angle iron terminate in welded attachment to a tubular hammer guide 22 shown as being square in section to slidably receive a hammer 23 of like section. For precise hammer movement the hammer and its guide will closely correspond in size and shape with wall clearance not exceeding more than a quarter of an inch.

An elongate door opening 22A is formed in one wall of hammer guide 22 and enables insertion of a post into the tubular hammer guide for driving by the hammer subsequent to hole forming. A door at 24 normally closes the opening and is remotely operated by a hydraulic cylinder 25 whose base end is swingably carried at 26 by an angle iron of the hammer guide assembly. The door pivots at its lower end at 27.

The hammer guide assembly 18 additionally includes a pair of pneumatic cylinders at 30 for urging said assembly and particularly the ground engaging end of the hammer guide into ground penetration as seen in FIG. 1. Pressurizing of the cylinders 30 will cause their piston rods 31 to exert a downward force on the hammer guide 22 causing the end'of same to penetrate the ground and act as a casing for the hole being punched by the hammer. The two cylinders 30 are base mounted to the framework crosspiece 12 by clevises in an oppositely offset manner (FIG. 4) while their rod ends are attached at 32 by clevises carried by the angle irons of the hammer guide assembly. Air lines (not shown) supply the upper ends of cylinders 30 to charge same causing continuous downward biasing of the hammer guide end into ground penetration as shown during hammer operation with the hammer leading the way to the depth desired. The post is then inserted into the guide with additional blows. seating the post.

Upward movement of the hammer guide assembly at the end of a hole forming operation is effected by a length of cable 33 reeved over pulleys of the later described support structure and in symmetrical bridle attachment with a winch powered cable 34. Such lifting movement of the hammer guide assembly 18 is independently of the hammer movement with the hammer desirably being left in resting contact with the post end during lifting of guide assembly 18.

A support structure is indicated generally at 40, from which the earlier described framework 10 depends with the support structure being best viewed in FIGS. 3-5. The support structure is supported by later described hydraulic masts for elevating said support structure and the upright framework 10 relative to the vehicular base 1 to suit the ground conditions at the job site. The support structure includes upper and lower turntables 41-42 with the latter secured in place on the framework crosspiece 12. An open sleeve 43 centrally cable 65 and is threaded to receive a lock nut and washer assembly 44 to retain the turntable members.

Welded to the upper turntable member are pairs of upstanding plates 45 with each pair laterally braced at 46. The pairs of plates 45 each terminate upwardly in sleeves 47 which in turn are carried by a supporting shaft 50.

The foregoing portion of the support structure serves to support the framework in a depending manner from shaft 50 and permits movement of the framework about the offset horizontal axis at y of said shaft. Rotational movement of the framework 10 is additionally provided for by the turntable structure described and occurs about the downwardly projected axis x of the sleeve 43 which is coaxial with the axis of the framework 10. The latter rotational movement is achieved by hydraulic positioning cylinders 14 and 16 earlier described.

With continuing reference to the supporting structure, that portion supporting shaft 50 in place will now be described.

A pair of extensible masts are indicated at 51 each including a hydraulic cylinder 52 housed within a mast and operable to extend a telescopic mast member 51A. The masts 51 are each hingedly mounted as at 58 while the upper ends of members 51A are interconnected by a connector plate 54 of the support structure from which projects a fixedly mounted spindle 55 (FIG. 4). Mounted on spindle 55 and movable about the axis 2 thereof is a sleeve bearing 57 with a cap 60 in secured spindle attachment to act as a retainer for bearing member 57. A thrust washer 61 is at the lowermost end of bearing member 57. To permit hydraulic deactivation of the cylinders 52, locking pins 53 are insertable through aligned openings in each mast and its telescopic member once adjustment is completed.

Welded to the sleeve bearing 57 are two upwardly directed supports 62 mounting integral collars at 63 within which shaft 50 is journalled. Intermediate the supports 62 is a cable sheave 64 for the hammer cable 65 which sheave embodies a roller bearing 66 (FIG. 5) to permit sheave rotation independent of the rotation of shaft 50.

The above described spindle 55 and sleeve bearing 57 constitute a first pivot means permitting gravitational movement of the framework 10 about the axis 2 of the spindle. A second pivot means comprises the shaft 50 and sleeves 47 which permit movement of the framework 10 about the axis of shaft 50 indicated at y. The axes z and y are offset and normal to one another.

For positioning and maintaining the support structure 40 and hence framework 10 a pair of hydraulic support cylinders at 70 are mounted in tubular housings 71 with their piston rods at 72 terminating in pivotal attachment at 73 with the support structure. Specifically, pivot pins at 73 extend through rearwardly projecting ears 74 welded to the supports 62. Accordingly extension of the piston rods 72 will cause movement of framework 10 about axis y.

The support cylinders also act in conjunction with the mast cylinders 52 to locate the framework 16 both outwardly of the vehicular base 1 and spaced vertically from the ground surface in which the hole is to be formed. In the driving of holes for guard rail posts the framework 10 will be suspended in a plumbed manner since all guard rail posts are driven on the true vertical.

An additional function of cylinders 70 is the tilting of the framework 10 rearwardly for highway travel for vertical clearance purposes. For such travel the piston rods 72 of the cylinders are extended while the rods of cylinders 14 and 16 are retracted causing the framework 10 to be tipped rearwardly with respect to the vehicular base 1. Obviously, during such inclination of the framework the crane machine 3 will be swung ninety degrees from its position in FIG. 1 so as to locate the framework 10 spaced from the trailing end of said base.

In a typical hole forming operation adjacent a roadway the mast length will be adjusted to space framework 10 above the ground surface. Cylinders 70 of the support structure will be extended or retracted subsequent to adjustment of the masts 51 to move the framework 10 into a vertical or plumb condition. For assuring the plumbed condition of the framework a pair of site levels 75-76 (FIG. 2) are located upon the guide retention plate 13 of FIG. 2 which are observed by the machine operator seated at 5. Operation of hydraulic cylinders 14 and 16 allows the operator to accurately spot the lower end of the framework. The crane machine being mounted on turntable 2 may of course swing horizontally during this spotting of the framework 10 over the hole site. Cylinders l4 and 16 may be additionally actuated for rotating the framework about its axis x such requiring opposite movement of the cylinders piston rods. With the framework now in plumb and accurately supported over the hole site, cylinder 15 is locked by closing of the valve 19A, earlier described, shutting off the two hydraulic lines serving the fore and aft ends of the cylinder. Simultaneously cylinders 14 and 16 are put in a hold condition by the operator with fluid pressure trapped on both sides of end pistons.

The two pneumatic cylinders 30 are subsequently pressurized to extend their piston rods and hence the hammer guide assembly 18 to cause initial ground penetration of the lower end of the hammer guide 22. The cylinders are left in a pressurized condition throughout the following described impacting of the hammer 23. Both ends of the tubular hammer guide are retained against lateral displacement.

Repeated lifting and dropping of hammer 23 by the cranes winch mechanism results in impact forming of the hole with the hammer guide end automatically functioning as a casing for the hole as the hammer guide follows the hammer into ground penetration. Impacting of the hammer is continued until such time as the upper end of hammer 23 approaches a selected indices alongside site opening 24A in the door 24. In the setting of guard rail posts the hole will desirably be of a depth somewhat less than the installed depth of the post as in a typical post driving operation the post is driven somewhat beyond the hole depth to assure secure post installation.

An important feature of the present machine is embodied in door 24 hingedly mounted to hammer guide 22, for the reason that a post may be inserted into the tubular hammer guide when the hole has been formed to the depth desired. The piston rod of cylinder 25 is extended by the operator to swing the door downwardly about hinge 27 whereupon a post may be laid on the door with closing of the door moving the post into the hammer guide. The inserting of the post into the guide may be accomplished without any risk to the workman as the workmans hands do not enter the interior of the hammer guide 22.

Operation of the hammer is again commenced with progress of the post into the ground being determined by a workman following hammer progress through the site opening 24A in the door 24. An additional site opening in the unseen wall of the hammer guide 22, opposite the door, permits the workman to view post depth with respect to previously driven posts. Upon the post being driven to the depth desired the pneumatic cylinders 30 are depressurized and an upward lifting force is imparted to the entire hammer guide assembly to lift same to remove the ground penetrating lower end of same from the ground. Such lifting being accomplished by the cranes winch mechanism acting through cables 34 and 33. The hammer is rested upon the driven post during removal of the hammer guide 22.

At all times during the hole forming operation the hammer is used as a ground impacting instrument with the casing functioning end of guide 22 being urged downwardly into the ground by pneumatic cylinders 30. Considerable time savings is realized by avoiding dual use of the hammer for both impacting and driving of the casing which is the case with some prior art machines.

The hammer 23 may be adapted to mount a replaceable cap at its lower end facilitating replacement of hammer end after long periods of use which will cause the metal to deform.

While I have shown but one embodiment of the invention it will be apparent to those skilled in the art that the invention may be embodied still otherwise without departing from the spirit and scope of the invention.

Having thus described the invention what is desired to be secured under a Letters Patent is:

l. A machine for impact forming a ground hole and post installation therein, said machine comprising,

a vehicular base supporting a crane machine having a prime mover, powered winches, and sources of pressurized media,

extensible masts pivotally mounted in their lower ends to one side of said crane machine,

an upright framework supported by said masts outward from said base and crane machine and positionable in axial alignment with a ground hole to be formed, said framework comprising, parallel guides extending lengthwise of said framework, guide retention plate interconnecting the guides adjacent their lower ends, hydraulic cylinders coupling the retention plate to the crane machine, hammer for reciprocal movement axially within said framework for impact forming of a ground hole,

a hammer guide assembly positionably carried within said framework and including, slide members cooperable with said parallel guides,

a tubular hammer guide carried by the slide members,

pressure responsive cylinders for urging said hammer guide continuously into ground penetration during operation of the hammer in a hole forming operation whereby the ground penetrating portion of the guide acts as a hole casing, said last mentioned cylinders causing said hammer guide to follow downwardly hammer progress,

a support structure for said framework located at the upper end of the framework and coupled to the crane machine by said masts, said support structure including, turntable means permitting relative movement between the support structure and said upright framework about the upright axis of the latter,

a shaft vertically spaced from said turntable means,

a first pivot means for movement of the support structure and the framework depending therefrom about a first substantially horizontal axis,

a second pivot means for movement of the support structure and the framework depending therefrom about a second substantially horizontal axis,

cable reeving means carried by said shaft with cable means reeved therethrough and terminating in hammer attachment, additional cable means terminating in hammer guide assembly attachment with each of the cable means being winch powered,

supporting cylinders coupling the support structure to the crane machine, said cylinders operable to move the support structure and hence the depending upright framework about said second pivot means into axial alignment over a hole forming site, and g the lower end of said framework and the hammer guide assembly therewithin being additionally positionable and lockable in a plumb condition by said hydraulic cylinders coupled intermediate the retention plate of the framework and the crane machine.

2. The machine as claimed in claim 1 wherein said tubular hammer guide includes a door closing an elongate opening in said guide, said door positionable to admit the insertion of a post into the said guide for subsequent driving by the hammer.

3. The machine as claimed in claim 2 wherein said door and the opposite wall of the tubular hammer guide define site openings to view hammer and post driving progress.

4. The machine as claimed in claim 1 wherein said hydraulic cylinders coupled to the guide retention plate of the upright framework are additionally operable to move said framework rotationally about its upright axis.

5. The machine as claimed in claim 1 wherein at least one of the hydraulic cylinders coupled to the guide retention plate of the upright framework is a locking remotely actuated shut off valves in communication with hydraulic lines serving each end of the locking cylinder.

7. The machine as claimed in claim 1 wherein said first pivot means comprises a spindle mounted sleeve, said second pivot means comprises a pair of bearing sleeves mounted on the shaft of the support structure. 

1. A machine for impact forming a ground hole and post installation therein, said machine comprising, a vehicular base supporting a crane machine having a prime mover, powered winches, and sources of pressurized media, extensible masts pivotally mounted in their lower ends to one side of said crane machine, an upright framework supported by said masts outward from said base and crane machine and positionable in axial alignment with a ground hole to be formed, said framework comprising, parallel guides extending lengthwise of said framework, guide retention plate interconnecting the guides adjacent their lower ends, hydraulic cylinders coupling the retention plate to the crane machine, a hammer for reciprocal movement axially within said framework for impact forming of a ground hole, a hammer guide assembly positionably carried within said framework and including, slide members cooperable with said parallel guides, a tubular hammer guide carried by the slide members, pressure responsive cylinders for urging said hammer guide continuously into ground penetration during operation oF the hammer in a hole forming operation whereby the ground penetrating portion of the guide acts as a hole casing, said last mentioned cylinders causing said hammer guide to follow downwardly hammer progress, a support structure for said framework located at the upper end of the framework and coupled to the crane machine by said masts, said support structure including, turntable means permitting relative movement between the support structure and said upright framework about the upright axis of the latter, a shaft vertically spaced from said turntable means, a first pivot means for movement of the support structure and the framework depending therefrom about a first substantially horizontal axis, a second pivot means for movement of the support structure and the framework depending therefrom about a second substantially horizontal axis, cable reeving means carried by said shaft with cable means reeved therethrough and terminating in hammer attachment, additional cable means terminating in hammer guide assembly attachment with each of the cable means being winch powered, supporting cylinders coupling the support structure to the crane machine, said cylinders operable to move the support structure and hence the depending upright framework about said second pivot means into axial alignment over a hole forming site, and the lower end of said framework and the hammer guide assembly therewithin being additionally positionable and lockable in a plumb condition by said hydraulic cylinders coupled intermediate the retention plate of the framework and the crane machine.
 2. The machine as claimed in claim 1 wherein said tubular hammer guide includes a door closing an elongate opening in said guide, said door positionable to admit the insertion of a post into the said guide for subsequent driving by the hammer.
 3. The machine as claimed in claim 2 wherein said door and the opposite wall of the tubular hammer guide define site openings to view hammer and post driving progress.
 4. The machine as claimed in claim 1 wherein said hydraulic cylinders coupled to the guide retention plate of the upright framework are additionally operable to move said framework rotationally about its upright axis.
 5. The machine as claimed in claim 1 wherein at least one of the hydraulic cylinders coupled to the guide retention plate of the upright framework is a locking cylinder to prevent undesired framework displacement relative to the crane machine during a hole forming and post setting operation, the remaining hydraulic cylinders additionally serving when in a hold condition to supplement the locking action of the locking cylinder.
 6. The machine as claimed in claim 5 wherein said locking cylinder is individually serviced by a separate fluid circuit including a source of pressurized fluid and remotely actuated shut off valves in communication with hydraulic lines serving each end of the locking cylinder.
 7. The machine as claimed in claim 1 wherein said first pivot means comprises a spindle mounted sleeve, said second pivot means comprises a pair of bearing sleeves mounted on the shaft of the support structure. 